Chair control with support for the torsion spring

ABSTRACT

A chair control for tilting chairs and posture chairs having a coiled torsion spring oriented in a horizontal plane with its axis parallel to the pivots on which the control tilts. The chair control has two frames which are pivotally connected to permit relative pivotal movement, one of the frame members being mountable on the top end of the chair post which is carried by the chair base. The torsion spring is supported by a fixed frame of the chair control so that it is fully supported thereby both when at rest and when subjected to torsional stresses induced by a person sitting in the chair when such person leans back in the chair.

I United States Patent [1 13,601,444

[72] Inventor Joseph T. Doerner [56] References Cited 7 wfltsrlwOntario, Canada UNITED STATES PATENTS {5;} gm 12 1969 2,202,630 10/1970Hauber 5/309 ux Patented g 1971 3,339,973 9/1967 Doemer 297/300 [73]Assignee Doerner Products Co. Limited Primary ExaminerJames C. MitchellWaterloo, Ontario, Canada Attorney-George H. Riches 32] Priority Sept.23, 1969 [33] Canada [31 062,731

ABSTRACT: A chair control for tilting chairs and posture chairs having acoiled torsion spring oriented in a horizontal [54] WITH SUPPORT FOR THEplane with its axis parallel to the pivots on which the control 2 Claim3 D F tilts. The chair control has two frames which are pivotallyconrawmg nected to permit relative pivotal movement, one of the frame[52] U.S. Cl 297/300, members being mountable on the top end of thechair post 248/383 which is carried by the chair base. The torsionspring is sup- [51] Int. Cl A47c 3/00 ported by a fixed frame of thechair control so that it is fully [50] Field of Search 5/309; supportedthereby both when at rest and when subjected to torsional stressesinduced by a person sitting in the chair when such person leans backinthe chair.

PATENTEU AUB24 l9?! Invenror fi p T- Doerner AHorney CHAIR CONTROLWITI-I SUPPORT FOR THE TORSION SPRING I BACKGROUND THE INVENTION Thepresent invention is an improvement on the chair control disclosed in myprior Canadian Pat. No. 771,456 dated Nov. 14, 1967 and its UnitedStates counterpart, U.S. Pat. No. 3,339,973 dated Sept. 5, I967. In thatstructure the torsion spring was supported on a nylon bushing carried onthe pivot pin connecting the cooperating pivot elements of the chaircontrol. The pivot pin is thus subjected to considerable strain which,in time, distorts and fatigues the pin.

I have found that the aforesaid-problem can be solved by supporting thespring on a pad, such as nylon, the pad, in turn, being supported on oneof the frame members of the chair control, preferably the fixed framemember which is mounted on the chair spindle.

DESCRIPTION OF THE INVENTION The invention will be described as appliedto a secretarial chair but it is to be understood that this is by way ofillustration only since it is obvious that it can be used with otherkinds of chairs.

For an understanding of the present invention and its advantages,reference is to be had to the following description taken in conjunctionwith the accompanying drawings. in which:

FIG. 1 is a perspective view of a tilter chair employing the chaircontrol of the present invention;

FIG. 2 is a side elevation in cross section through the center of thechair running from front to back thereof to show details of theconstruction; and

FIG. 3 is a cross-sectional view taken on the same line as FIG. 2 withthe back tilted.

FIGS. 1-3 show the present invention as applied to what is commonlyknown as a posture or secretarial chair.

The posture or secretarial chair incorporates a modified chair control Adesigned to provide yieldable, backward-tilting support for a tiltablechair back pivotally connected to the chair seat 11 through the mediumof the chair control A, the seat in turn being fastened to the controlas herein described.

The chair control includes a first frame structure 14 which includes aplate 16 apertured to receive the spigotted end of the spindle l2 and abushing 13 rigidly attached to the plate l6 with the apertures'insidewalls 15. A hinge pin 21 is mounted through the said apertures toconnect the first and second frames for relative-pivotal movement.

Tilt-resisting spring-biasing means 22 are provided for the chaircontrol to urge the chair back 10 to a normal or first position asillustrated in FIG. 2 and resist movement to the second position asshown in FIG. 3.

The aforementioned spring-biasing means 22 comprise a torsion spring 23including pair of oppositely wound coils 24, 25 coiled about the hingepin 21 and mounted between the spaced-apart sidewalls 15. The torsionspring 22 also includes oppositely extending ends 26, 27 of each of saidcoils 24, 25

' and a first end 28, 29 of each of said coils 24, 25 is joined by a andapertured to receive the shank of the spindle 12. The first connectingportion 30. The connecting portion 30 is connected to the first framestructure 14 by connecting means comprising a threaded rod 31 which ishooked at one end over the connecting portion 30 and which extends atits other end through the plate 16 and is threaded into a manuallyoperable tension-adjustin2g nut 32 for the sprin -biasing means 22, saidad usting nut 3 being easily accessib e on the outside of the firstframe member 14.

The hinge'pin passes centrally through the coiled tension spring asshown. The spring 23 is on a support pad 33 which extends under thespring between the spaced-apart sidewalls 15. The pad 33 is preferablymade of nylon and has its upper surface concaved to the curvature of thecoils. The concaved surface forms a recess into which the coiled springseats, the spring being thereby restrained against eccentricdisplacement when the spring is torsionally twisted. The pad 33, inturn, is supported, on the base portion 34 of the frame 16 in closeproximity to the bushing 13. The forces created by the torsion springare thus carried on parts adapted to carry heavy loads.

What I claim is:

l. A chair control having:

a. a first nontiltable frame mountable on a chair base;

b. a second tiltable frame member;

c. a helical torsion spring operatively connected to the frame membersto resist relative movement of the frame members in one direction;

(I. a hinge pin pivotally connecting the frame members together forrelative pivotal movement, said pin extending axially through thetorsion spring; and

. a spring support pad mounted on the first frame underneath the torsionspring, said pad having its upper surface concaved to receive thereinadjacent portions of the spring in free slidable relationship wherebythe forces generated by the torsionally loaded spring are carried solelyon said support member and the spring is restrained against eccentricdisplacement.

2. The invention according to claim 1 in which the torsion springcomprises a pair of oppositely wound coils connected together by arearwardly extending connecting portion and the spring support pad beingdivided into two spaced-apart sections forming a passageway throughwhich connecting portion extends, each section supporting one of saidcoils.

1. A chair control having: a. a first nontiltable frame mountable on a chair base; b. a second tiltable frame member; c. a helical torsion spring operatively connected to the frame members to resist relative movement of the frame members in one direction; d. a hinge pin pivotally connecting the frame members together for relative pivotal movement, said pin extending axially through the torsion spring; and e. a spring support pad mounted on the first frame underneath the torsion spring, said pad having its upper surface concaved to receive therein adjacent portions of the spring in free slidable relationship whereby the forces generated by the torsionally loaded spring are carried solely on said support member and the spring is restrained against eccentric displacement.
 2. The invention according to claim 1 in which the torsion spring comprises a pair of oppositely wound coils connected together by a rearwardly extending connecting portion and the spring support pad being divided into two spaced-apart sections forming a passageway through which connecting portion extends, each section supporting one of said coils. 